Hi there, My question concerns “Non Ionizing Radiation”. As a part of roof maintenance, the company I work for will employ subcontractor to undertake repairs for the duration of 12 weeks, on the top of high building, which contains a few mobile phone transmission masts, situated in a very close proximity (less then a meter from the working areas). Naturally, the usual risks associated with the work activities related to the specific tasks at hand have been evaluated and controlled. So here comes the “grey area” question: Can anyone shed light regarding the occupational exposure to ”non ionizing radiation” in particular the one generated from mobile phone transmission masts. I have already consulted with the HSE, IHS, HPA web sites, yet I have to admit the information found was limited and not up to the point. Studies related to the subject are outdated and often filled with technical jargon, which does not simplify the issue. Unsupported studies show increase likelihood of developing a range of debilitating symptoms, which in some cases may lead to cancer etc. I have already established that the exposure values in UK differ with regards to “members of the public” and “workers”. Furthermore, researching the subject added more insight concerning planning permission regulation. Apparently, Mobile Phone masts should not be installed close to schools with a minimum of 250 m being the quoted figure as approved distance. Maintenance personnel working for mobile phone companies, among many other industries are certainly exposed to “non ionizing radiation” occupationally, but why does it prove difficult to come with simplified way of stating what the occupational exposure limits are and subsequently a weighted average figures produced and approved by one of the many regulatory bodies here in UK in order to assist Safety Practitioners. Would you suggest that relying on the companies’ own database, should they decide to share it, is considered to be credible, or would you rather take your own measurements and act accordingly. In an ideal world following the hierarchy of control, the elimination approach (switching the masts off) should serve the purpose, yet I am dreading this will prove impractical, so your suggestions to limiting the exposure in addition to any advise or sample RA/MS would be greatly appreciated. Regards.

This is a point that has always intrigued me. What is the difference between the radiation emitted by a mobile phone and that of the transmitter? After all, the power from the mobile phone must be sufficient to interface with the transmitter and a mobile phone is held directly against the head, i.e. in close proximity to the brain. Chris

The handset interfaces with base station. This then commands different levels of power for the handset transmitter, and a change of frequency. The base output power does not vary from h/set to h/set. Since the base antennas exhibit considerable gain a person within a very short distance from the transmitter antenna on the base could be exposed to several hundred watts of rf. That exposure is reduced by distance, double the distance quarters the power. The handset power is about one watt. Same power reduction with distance.

The antennas are the issue here if you will be working 1 metre away, you need to contact the mobile operator to arrange an outage. Remember plenty of notice, as previously mentioned you don't want a 'soft' shut down done remotely - request a engineer attendance to site 'hard' shut down. You can work right up to the transmission dishes, as they operate at extremely low power - the Orange ones do anyway, not sure about the rest. Operators use the guideline set out by ICNIRP, occupational safety distances.

Thanks for the responses guys. We are meeting with the client and representatives from the mobile phone company to establish what the particular emission values of the antennas and transmission units are, before we finalize our approach with regards to implementing suitable and sufficient control measures. It is an interesting topic, which has been bugging me for some time and it just happened that I had to research it as apart of my occupational day-to-day safety duties. Regards,

I had this situation a number of years ago. Within the immediate proximity of the transmitters it is possible to exceed the exposure levels in the codes of practice. As Johnmurrey says the power fall of as it is distance dependent, it is the inverse square rule if I remember correctly Unfortunately we discovered that the transmission company were not very helpful and restricted the times when they were prepared to close the transmitters down The contracts they have with your site will be very restrictive. We finally agreed block times when they would shut down during the day. I suspect you will have big problems if you need a full 3 month shut down. Unless there is another transmitter site close Its worth remembering that some high buildings have TV boosters on them to cover blind spots And in some cases also have to be shut down while roof maintenance is carried out The natives do get restless if they can not get Corrie or Eastenders.